Looking to farm this in MP as the solo method is horrible and not yielding results.
Took the process from a subreddit with user deleted - thanks unknown friend.

Hope we can get 2 to knock this out!

The Process

• Get two friends
• all three of you either level up to SL 20 and have at least one +7 or +8 weapon (might want to rush dancer) or level to SL 70 or some other higher SL without ever leveling your weapons.
• go to a location, where the multiplayer isn't booming and the boss is alive for the future host, like the ariandel chapel.
• friend 1 embers up, equips way of the blue, uses dried fingers
• friend 2 equips aldrich faithful and invades via red eye orb
• you equip blade of the darkmoon and wait to get summoned
• once you reach their world, invader suicides. You get a proof of a concord well kept = two proofs
• repeat.

Looking to farm this. Worst part of the game!

1. Equip the warriors of sunlight covenant.
2. Have a friend meet you at anor londo bonfire.
3. Lay down your red soapstone sign.
4. Your friend then summons you.
5. Soon as you COMPLETELY spawn in, your friend jumps off the ledge to his death.
6. Receive sunlight medal
7. Repeat 29 more times

Steps taken from deleted user on another subreddit. Message if you want to do this and we'll work out a time. Alternating of course.